Zolmitriptan

Zolmitriptan is absorbed rapidly following oral ingestion, but has limited bioavailability (F = 0.5). Peak blood concentrations are achieved within 2 hours. The ingestion of food does not affect the bioavailability of zolmitriptan. Zolmitriptan is metabolized in the liver and has an active metabolite, N-desmethylzolmitriptan. Zolmitriptan and its active metabolite are only minimally bound to plasma proteins. Concurrent alcohol use may increase the CNS depressant action of zolmitriptan. Concurrent propranolol pharmacotherapy may significantly inhibit the metabolism of zolmitriptan. This interaction may result in increased zolmitriptan blood concentrations and a longer half-life of elimination of zolmitriptan, but lower blood concentrations of its active metabolite (i.e., N-desmethylzolmitriptan). These pharmacokinetic changes appear to largely counterbalance each other and negate the need for dosage adjustment. However, patients should be carefully monitored and the dosage of zolmitriptan adjusted accordingly. Clinical data concerning zolmitriptan overdosage are not available.